Question

19
If the median of the distribution given below!
28.5 find the values of xandy.
frequeny!
Glass internal
-
10-20
20-30
30-40
4o-so
50 60
Total​

Answer 1

Answer:

n/2 - cf

 We know that Median =  l +   ----------   * h          ---------- (1)

                                                      f

Given that Median = 28.5.

CI                F            Culumative Frequency

0-10            5                   5

10-20         x                    5+x

20-30        20                 20+5+x = 25+x

30-40        15                  25+x+15 = 40+x

40-50        y                    40+x+y

50-60       5                    40+x+y+5 = 45+x+y

Total         60                   

45 + x + y = 60

x + y = 15    ---- (2)

Given n = 60  ---- (3)

Cumulative Frequency of class before median cf = 5 + x.  ----- (4)

f = 20   --- (5)

Substitute (2),(3),(4),(5) in (1), we get

28.5 = 20 + (60/2 - (5+x)/20) * 10

8.5 = 25 - x/2

x = 25 - 17

x = 8.

Substitute x = 8 in (2), we get

8 + y = 15

y = 15 - 8

y = 7.

The values are x = 8 and y = 7.

Hope this helps!